Interoffice telephone system



.MMDL mm on lNvENToR WWU- RED T. POWELL.

5 sheets-smet 1 BY p9 W. T POWELL INTEROFFICE TELEPHONE SYSTSEM'` FiledApril 4,

May 20 11924.

May. 2o, 1924.

' w. vr. POWELL. IN'EaoFFIcE TELEPHONE lSYSTEM Filed Aprn 4, 152xlNvENoR wmFREpT POWELL BY Q gg'amw` ATTORNEY May 2o, 1924 I 1,494,866

W. T. POWELL n leq April 4 1921 5 sheets-sheet 4 ATTORNEY May 20, 1924.1,494,866

W. T. POWELL I NTEROFFICE TELEPHONE SYSLI'EM Filed April 4. 1921 ssheets-sheet 5 INVENTOR N y WIHF'REDTPOWELL ATTORNEY FIGS Patented May20, 1%24.

Wiiiirnnn fr. POWELL, orsoorinsrnaivnw Yoan,i-irssrenonnro'rI-insTRoi/JL'BERG CARLSON TELEPHONE MANUiii-ecruBrive contrasti?, orROCHESTER, NEW YORK, A'

CORPORATION OF IIEVJV YORK.

nrnnorrrcn VTELErHoNpE' sYs'rr/iiir'.

Appiicatikin4 fried April '4, 192i." yse'iia'i ini.` 453318.

To kfaZZ whom #may 0on0ern:.

Be it known that I, VINFRED T,y POWELL,

a citizen of the United` States, residing at.

Rochester, iii the county of Monroe and State of New York, haveinvented.certain` new and useful Tinproveinents inlnteroiiiceV TelephoneSysteni's,of which the following.

' is a full, clear, concise, and exact description. l z

This invention relates to telephone systems and more particularly` thesysteniseniploying automatic switches'to establish" some part of atelephone connection. Y

Iny inter-office telephone systems, it. has

formerly been necessary to provide an ,in-

struction circuit between operators at the 1 Y. this figure. andvfunctions vto pre-select-` .an

exchanges through which, a telephone'connection is to be extended.V Thisinstruction circuit commonly known as an order Vwire is employed toconvey instructions between the operators las to thelines and trunks tobe used iii the connection. As aresult of the use of this instruction ororder wire,

the service is rendered less vrapid by reasonA of the fact that thewanted number must be repeated to the operator at the exchange where thewanted line terminates, and this operation, in addition to the slowingvdown of the service, is a source of numerouser-r -rors due to the factthat the numbers are notrepeated distinctly., Y Y

VThe ypresent invention has for its .purpose the elimination of thementioned instruction or order wire, aswell as to provide novel meansfor facilitatingvthe establishnient of a telephonerconnection. `Thesevarious features will appear from the following detailed descriptionaiidclaiins:

The drawings with Figures l and v2 arranged in the order named, and`with Fig.- ure placed below Figure l, diagrammatically, represent aportion. of a telephone systeni employing ,the present invention. At

the upper left-hand corner of Figure l there," is represented the lineand sub-station `cir-V cuits of a subscriber and multiple jack of thisline. There is also represented an abbreviated cord circuit terminatingat each end in a well-known connecting plug.. ThisI cord circuit may beof any well known type employed forv extending inter-oliice ltele-Vphone connections. Iii this figure there also appears .the oper-atingIcircuits l of av .y

selector switch of the two-motion type vvlilrl functions to first selecta; group L 0f- `trunks'.

selectsan `,idle r,trunk iiithefs'electedi group.:

A trunk finder'switchlocating the *trunk*Y to be. seized f by the.ltrunk selector..V and a senderlinder for selecting@ pre-selected ,reg-A"idle sender foruse ahead ofthe calls. .These various switches 5and the.operating: circuits.

for the saine areeiic'lo'sed .by `Olottedqlinesi` and` by the confines`,ofthe drawing. the lower; left-hand .portion ,of Fig. '1.,t-heifeappears a single stiiplof ten, numerical keys.i

whichfisconinion toa single positio'nr'iif; the

switchboard. In Fig.l Sfthere' is represented a register senderincluding.a vcontrol or.V

sender switch individual to;` this sender. '.It will be understood. thatthe arrangements',V

appearingv in Figs;v l and' .3 arelocated in the saine oiiice.. "InFigure A2ftliere. isfdiagraininatically 4showna portioiilof the trunkcircuit at the second or distant,QOice,and.,

the controlling Y. circuits'` for'lr the l, saine. V{Tn this ligure,there also appear" group`s` of.y rye-.Y

A 4lays. for receivingfthe designation from the vregisters of; theoriginating officel andareceiver switch forco-.operatingin the trans-1fer ofthisdesignation tothe groups of receiving relays.

Figures 1 and 15,:representA the ,trunk and.`

controlling.,.circuits associated therewith atk the distantoiiice aswell as the modifiedtre.-

ceiving registers `and rlainp indicatinggdee.

vices associatedtherewith. `Itwill be un: derstood that the .circuitsofFigures 4 ,and

5 may besubstituted for, those ofdigure 2,;

in which casel` the circuits Y. lof, Tiigures. if and'.

5 operate .with thoseinFigures 1.andi3.. The switchesemployed in .this.systeni5- with. the exception of,.the trunk',selector switches mayA be,substantially gsiinilar, ,iii

structureto those disclosed in thepatent to 55 leading to the wantedoflicef,andthereupon Clement No. 1,107,153'patented'August 11, 1914. Thetrunk selector switch may be similar to that disclosed in theY patent toKeith et al No. 815,321 patentedl March 13, 1906.

The various portions of the equipment of the system may be arranged inthe follow-v indicating that the registers of the preselected 'senderare in readiness to'b-e ad' justed under control of the key-set, and astartkey for releasing the key-set from the operated register'sender.VVA wipe-out key is also provided for each position to release vregistersthat are inaccurately adjusted.

Before each operator there are placed groups of multiple trunk jacksconnected to trunks, each group/or' which is assigned for.

calls destined to a particular exchange or ofce. These multiple trunk)acks are connected to primary trunks each of which ter.

minates at its other end in a two-motion selector vswitch operating toseize the secondary trunk circuit indicated by a trunk finder switch.The number of trunks and thel number of two-motion selector switches ofcourse will depend upon the amount of traffic. switches and multipled toother similar switches at other operators positions is a secondary groupof trunks leading to dietant oilices. In this system there are provideda plurality of register senders each comprising a group of relayregisters and a rotary control switch or sender switch. These registersenders are common to all the positions at the originating office andwill be sutiicient4 in number to care for the maximum number of callsthat are in process of completion at the same time. A senderpre-selector switch is provided for the individual use of each operatorsposition and runctions to preselect an idle register sender for itsindividual position ahead of the call. VIn order to associate an idleregister sender with an idle secondary trunk circuit t0 the wantedoiice, a series of link circuits common to a plurality of operators areprovided. Each of these link circuits terminates at one end in a trunkfinder switch having multiple terminals of the Vvarious secondary trunkcircuits and serving Vto select an idle secondary trunk circuit,

and at its other end in a sender finder switch ,functioning to locate apre-selected register sender. In order to select one of these linkcircuits and to start a trunk finder and a sender finder switch intooperation, link linder switches are provided of which there To theterminals. of these two-motionY subscribers sub-station indicated 'at Ato a wanted subscribers station indicated at B l/Vhen the callingSubscriber at A removes his receiver from its switchhook, the line relay2 is operated in the wellknownv manner and actuates the line signal 3.The operator thereupon inserts the plug e into multiple jack 5 of theVcalling line. rlhis operation is eifective to actuate the cutoff relay 6which functions to disconnect the line relay 2 from the calling line andto ex- Y tinguish the line signal 3.V The operator thereupon depressesthe listening key LK to connect her telephone set (not shownltothecalling line and Vthereby receives the designation of 4the wantedline'from the calling subscriber. All of this takes place Vin thewell-known manner.

Let it be assumed that the designation of the wanted line is Main 2345-JThe operator then inserts the calling'plug 7 into any one of a group ofjacks, such as 8 assigned to the exclusive use of calls completedthrough the Main exchange. As soon as this operation is complete, acircuit is closed from grounded battery through the sleeve of plug 7 andsleeve of jack 8, winding of the marginal relay 9, its armature and backcontact, winding of the slowereleasing relay 10, conductor 16, lowerback contact and armature of relay 11, uppermost back contact andarmature'of relay 12 to ground.

cuit, but the relay 10 is operated to fclose other circuits which willbe described. One

` of these circuits extends from ground, front contact and armature ofrelay 10, lower liigh-resistance winding off the relay 13, thenormally-closed contacts of the wipe-out key, continuity spring and backcontact ofv the slow-releasing relay 14, winding of the marginal relay11, armature, back contact and winding of the motor magnet 15 to` ll() lldarginal relayv 9 is not actuated .in this cir"V erated in a circuittraceable from'grounded battery, resistance through the sleeves of theplug 7 andy jack 8,Winding ,of relay 9, its Continuity spring and backcontact, uppermost armature and front contact of relay 13, conductor 16,lowermost Vback contact and armature of relay 11, uppermost'back contactand yarmature of relay 12 to ground. Relay 9 on operation lclosesalocking circuit for itself throughits `continuity spring and armatureto ground. The relay 13 when operated'also closes a locking "circuit foritself and an operatingcircuiting for relay 11 through its lowresistance winding, this circuitbeingv traced Afrom ground, innerarmature and 'front contact of relay 13, armature and back contact ofthe relay 10 low resistance vwinding of relay 13 through the contacts ofthe Wipe-out key und through the windings of relay 11 and motor magnet15 to grounded battery.V

Relay 11 is thus energized and-effects the operation of relay 59 lin a'circuit closed from grounded battery, its winding, lowermost armatureand front contact of relay 11, uppermost back contact and armature ofrelay 12 to ground. The lamp 60 is lighted in multiple with relay A59 toindicate that the operators key set has been connected to an idleregister sender.l Relay 11 also completes operating circuits'for relays41 and 71 traceable from ground, winding of relay 41, innerront'contactand armature orelay 11, brush94, conductor 95, vwinding ofrelay 71 to grounded battery. Relay 71 when operated opens the releasecircuit of the sender switchV of Figure 3 `and connects the lockingground to conductor'70. With the locking ground connected to conductoran operating circuit 'is closed for the thousands switching relay 66,completed from grounded'battery, right-hand winding of this relay,middle armatures and back contacts of relays 73, 74, and 76 back contactand armature of relay 77 to ground over conductor 70. The switchingrelay when thus operated connects the opera-tors key set to thethousands relay register. Also when the relay 13 is operated, it'closesa circuit from grounded battery, resistance, lower armature and frontcontact' of relay 13, armature, back contact and winding Yoi? ,the motormagnet 17, continuity spring and back contact of relay 18 to ground.Under the control of this circuitthe motor magnet v17 advances thebrushes of the link iinder switch until the test brush 19 engages thetest terminal of an idle link circuit, which link circuit terminates atone end in a trunk .finder switch and at the other end in a senderiinder switch. vAs soon' as the idle link is located, a circuit isclosed for short-circuiting motorinagnet 17 and thereby stopping thelink inder switch, this eircuit being completed 'from groundedbat-Adered busy.

tery, resistance, `armature and -front contact of relay 13,lefthandWinding of relay 18, p test brush 19,v back contact and armature of.

winding of the motor magnet 17, continuity spring, armature and 'righthand winding of relay 18, holding brush 22, winding of theslow-releasingrelay 20: to ground; Relay 18 is maintained operatedinthis circuit,` but themotor magnet 17 is not actuated inl series withthe high resistance winding of the relay 18. Therelay 20 at its upperarmature removes the stopping ground potential-from all thetestterminals of this .link at other link finder switches' so that -it willbe ren- The'operation of the relay 20 lcompletes circuits 'for' settingthe trunk finder switch and the sender finderswitch oi the selected linkcircuit into operation. rIhe actuation of the iirst :of theser mentionedswitches vwill now be described.

Y As soon as the relay 20 actuates its arma tures it closes a-circuitfrom grounded battery through theresistance inner armature and frontcontact ofvrelay 20, back contact, armature and winding of the motormagnet 23, continuity spring and back contact of relay 24 to ground. Themotor magnetV 23 is actuated infthis circuit and advances the brushesofy the trunk finderl switchuntil the test brush v25 engages a testterminal of an idle trunk, at which' time a circuitV is closed 'i toground at'th'e armature and back contact` of relay 26, conductor 27 ,1test brush 25, lefthand low resistance winding of the relay 24,.frontcontact `and armature of relay`20 through the resistance togrounded'battery. This circuit is eiective to short-circuit the motormagnet 23 and lto actuate the relay 24. This last-named relay whenoperated closes a locking circuit `for itself from groundedbattery,resistance, armature and front contact of relay 20, .backcontact, arf ci mature and winding of the motormagnet 23, VcontinuityspringV armature and righthand high resistance winding of the relay 24,holding brush 28, upper winding of the marginal Arelay 29,- left-handwinding of' relay 26 through the back contact and armature to ground atsome other relaysimilar to 26 associated with an idle trunk `r`leadingto the Main'exchange. As 'soon as all the relays similar to26 areactuated the last-de -llil CII scribed circuit will extend through thewind-V ing of the group relay 21 which operates to remove the stoppingground from the terminals of all link finders assigned for use withtrunks leading to the Main exchange. Since relay 29 is marginal it willnot operate in the last described circuit but holds open the tip andring conductors of the selected trunk to prevent interference with theimpulse circuit including conductors 197 and 131. The rela-y 24 at itsinner left-hand armature and front' contacts applies ground overconductor 30 to the group terminal of the trunk selector switch toindicate the group ot trunks to be selected by this switch, 'whereasground is applied over conductor 31 to indicate the trunk that is to beseized in this selected group. At the outer lefthand armature ot relay24 a circuit is'closed from `grounded battery through the lamp` 32,inner armature and front contact of relay 18 through the brush ot thelink finder, outer front contact and armature of relay 24 to ground.Lamp 32 when lighted inlorms the operator that an idle; trunk circuit tothe distant otlice, as well as an idle register sender have beenselected, also at the outer armature and front contact of relay 24, abreak-point is closed in the operating circuit ot the relay 14, but thiscircuit is still incomplete at the starting they. The purpose ot thislast-mentioned circuit will be described in the course of the followingdescriptions.

The operation ot the sender finder vswitch will now be described: Itwill ot course be understood that the sender iinder and the trunk finderswitches operate simultaneously, the sender iinder switch being operatedby the closure or" the circuit trom grounded battery through theresistance',

lowerinost armature and front contact of relay 20, conductor 34, backcontact, armature andv kwinding of the motor magnet 85, continuityspring andback contact of relay 36 to ground. The sender'iinder switchadvances its brushes until its Vtesty brush 38 encounters a testterniinalof the pre-selected sender, at which time a circuit is closedfrom grounded battery resistance, lowerinost' ar mature and .Frontcontact of relay 29, lefthand low resistance, winding ot relay 36, testbrush 38,. conductor 39,'sender pre-selector brush 40, armature andfront contact ot relay 41 to ground. This circuit is efective to operatethe relay 36 and introduce resistance in the circuit of the motor magnet35 of thew sender finder to stop the same with its brushes in engagementwith the terminals of the pre-selected sender. The re lay 36 whenAoperated closes a locking circuit for itself from grounded batteryresistance, lowermost armature and `front contact of relay 20, conductor34, backcontact, armature and winding Yof the motor magnet indicate thatthe register sender of Fig. 3 Y

is busy. f

As soon as the marginal relay 9 is operated it closes an operatingcircuit for advancing the trunk selector switch. Here it should be notedthat the trunk selector operates practically simultaneously with thetrunk finder and sender finder, the operation of which has beenpreviously described. The mentioned operating circuit extends vtromgrounded battery, resistance, right hand armature and front contact ofrelay 9, continuity spring and back contact of relay 45, continuityspring and back contact of relay 46, armature, back contact and windingof the primary motor magnet 44, lower contact and'armature of relay 47to ground. Under the control of this circuit the primary motor magnetadvances the brushes of the trunk selector until the group brush 48encounters the group terminal 49` to which ground potential has beenapplied by the operation ot the trunk finder switch.. As soon as thisterminal is located the primary magnet 44 is short-circuited by acircuit which may be traced from grounded battery resistance, armatureandV front contact of relay 9, continuity spring and back contact ofrelay 45, continuity spring,back contact, lower winding ot relay 46,group brush 48, group terminal 49, trunk finder brush 50, inner frontcontactand armature of relay 24to ground. This circuit is eiective tostop the operation ofthe primary motor magnet and also actuates therelay 46 which immediately closes a locking circuit for itself fromground through its upper high resistance winding, its inner armature andcontinuity spring, back contact and continuity spring of relay 45, frontcontact and armature of relay 9 resistance to grounded battery. With therelay 46 operated an actuating circuit is closed for the secondary motormagnet from ground, the winding,

armature and back contact of this magnet, innermost armature andcontinuity spring of relay 46, back contact and continuity spring ofrelay 45, front contact and armature ot relay 9 through the resistanceto grounded battery. This circuit is effective to advance the brushes ofthe trunk selector switch in its secondary movements to hunt for thepre-selected trunk circuit in the selected group or" trunks. As soonasthe preselected truiik is located, a circuit is closed from groundedbattery, resistance armature and front contact of relay 9, continuityspring and contact of relay 45, uppermost tront contact and armature ofrelay 46, low resistance winding of relay 45, test brush iso Maase@ .52of the trunliselector, .conductor 81, :front contact and armature ofrelay24 to ground. The secondary motor magnet vis shunted, but therelai/,45 is actuated and closes a locking circuit for itself tromgrounded battery, resistance, 7armature andtront contact ot relay 9,continuity spring, .armature Aand high resist ance Winding of relay `45,holding brush .53

of the trunk selector, conductor 54, lower the trunk. selector until-thegroup brush ,48-

encounters the overflow terminal -57 to close an operating circuitlforthe relay 447. v:This ejects .thei-ellevase .of the trunk .selectorswitch by reason of 2a circuitclosed from grounded battery,`.resista-nce, armature vand Viront `contact ot relay .9, .upperWinding, front contact .and .armature .of relay ...47 .winch-ngerthereleaseimagnet 5.8 .andonormal contacts to ground. -This will releasethetrunksele'ctor switch andit .Will immediately.V repeat. ltheoperation. of. hunting for the preselected group of trunks and as soonasfthisI group ottrunks islocated the primary operation of the trunkselector switch Will. be stopped in the-manner already described. y

Assoon .asthe relay 59,is,operate d,the operatorsset .of keys ,is.connected Vto the brushes 61, .6263and 64othe sender2 preselector l.andysince vthis .pre-,selector is Vassumed to be standing with .its lbrushes in engagement with the yterminals of `an idle sender theoperators -key 4 setjis thus ,con- Ynected `to `an idle register sender.It has Vbeen assumed ,earlier in the. description that thevdesignation-of the Wanted Lline lsMain 2345TJ. The operation of pluggingintto a connecting jaclrassigned tothe Main o'ice con'llpletes the irst1part ot the selection. It y theretore remains orthe, operator tot setup theremainder-.of thedesignation 2345.-:J which is done by pressinglthe .respective keysin the order named.A

YWhen the operator presses key N o. 2, Va circuit is closed from groundythrough the contacts of thislkey, conductor', `armature and frontcontact of relay 59, brush 63, conductor (35, armatureland contact y67of relay (3G, lower ,Winding ofthe marginal yrelay 68, Winding ofrelfayvGQ to grounded Abattery to operate relay 69. Relay k68isoactuated in this lcircuit and completes a locking circuit for itselrP`from grounded batter Y, its up-V per Winding front contact Yandarmature, front contact and armatureV of relay 71.toy

. battery.

ground. The operation loit-relay ractuates relay 72. lVhen, howeyentheNo. 2ykey is released-relay4 69 deenergizesand retracts its armature,but an operating circuit; lsclosed tromgrourrd, its continuity springand back'. contact, lrlp-geht-hand Winding of relay 72,1135 .innerA-front -contact and armature, outer armatureland front ,conta-ct ofrelay 66,v righthand Winding of `relay 7 3 toI grounded "The Arelay y73is actuated in this circuit and is locked operated, first a circuit fromgrounded ibattery, its leftyhand winding, linner Vfront contact Vandarmature, `outer armature and front Contact o t vrelay 72-to ground.' Asecond, ylocking circuit for relay 7 3 extends from grounded battery,righthand Winding .of

this relay, its middle front contact `and-.ar-

mature through the middle back contacts 4.and armaturesotrela s 74 7 5and 476 back.

.con,tact. and armature of relay 77, conductor 70 to the Aholdingground. The operation ljustdescribed is etfective to selectively actuatethe thousandsrelay register and \has .extended the control or' theopcrators they-` lset to `thefhu-ndreds relay register. A The`0perator.nowfdepresseszkey No. 3 and thereby completes `a circuit fromground through the resistance, contacts of the No. 3 key, armaturevandfront Contact oi relay 59, brush 62, armature and front contact 7 9 of`relay v73, lower Winding of sensitive relay'BO, lower Winding ofthemarginal relay'81,Winding otrelay 69 tov grounded battery. The relays 8O.and rG9 .are actuated in Ethis circuit, vbut marginalzrelay 81 remainsinert. 'Relay -80 lon operation closes ;a 4locking circuit for it- .self,from grounded lbatt`ery,its :front coir ltact and armature tofgroundvover conductor 70. The relayvGS whenoperated again, ac-

tuates 7 2te effect the deenergization .of 'the switchingrelay 73 andIthe actuation ofthev tens switching relay 7,4 in the manner justdescribed for. therelays Itiand 7 3. Thatens register new in.readiness'nto be loperated and-the opera-tor depresses No. 4 keypotfherkey-set to closea circuit roinfground, contact-sof the No. 4 key,armature and'tront` contact o-frelay 59, Ibrush, 61, armature andcontact 82 otrela'y74, lower vWindingot Athe marginal relay v83, Windingotrelay 69v to ingrelayV 742the'n -deenergizes and vthe units groundedbattery. Relay 83 when Voperated lislocked operated` over a circuitincluding conductor 70fto the locking ground. Switchv.

manner =as has been `described 'iin connection .l

with. relay j 4e. The operator non7 depresses numerallrey ,No.5 andextends .the circuit from groundthrough thecontacts .of No. 5 key,armature and front Contact of relayv 59, brush 64, conductor84, armatureand contacts S5 of relay75, lower winding of sensitive relay 80 lowerWinding of marginal relay-87, Winding of relay 69. to grounded battery.Here also the sensitive relay 80 and Vthe relay 69 are energized,together with relay 87. Relays 80 and 87 on operation are locked in thiscondition over conductor 70 to the locking ground. Switching relaydeenergizes and relay 76 is operated in a manner similar to theoperation of relay 73. The operator now depresses the party key J whichextends a circuit from ground, resistance, contacts of key J, armatureand front contact of relay 59, brush 64, conductor 84, armature andcontact 89 ot relay 76, lower winding of relays 90 and 91 and winding ofrelay 69 to grounded battery. Relays 90 and 69 are actuated in thiscircuit, the former of these relays being held operated over conductor70 to the locking ground. Relay 69 etects the'operation of relay 72 tocontrol in turn the actuation of the relay 77 which is locked operatedover the locking ground conductor to remove thisf register sender fromthe further control of the operators key-set. The relays of the registersender remain in this actuated condition until the operator at thedistant olioe has signified that she is in readiness to receive theindication of the wanted party.

The operator after setting up the wanted number depresses the start keyand completes a circuit from grounded battery, resistance, upper contactof the start key, winding ot the relay 14, outer armature and frontcontact of relay 18, brush 33, righthand winding of relay 93, outerfront contact and armature of relay 24 to ground. Relay 14 is operatedin this circuit and opens the operating circuit of the relay 11 whichpermits the sender pre-selector to be advanced to select an idle sender.This is et fected by reason Vof the fact that the relay 12 is nowoperated in a circuit traceable from grounded battery, its'winding,lower back cont-act and armature oi'i relay 11, test brush 94 of thesender pre-selector, conductor 95 and front contact and armature toground, of relays similar to 4 3 at engaged register senders. Whilerelay 12 is held operated, motor ymagnet 15 is actuated in a circuitextending through its winding, back contact and armature, the inner'front con- `tact and armature o1z relay 12, lowermost sistance togrounded'battery. fit-h the relays 36 and 93 actua-ted, relay 92`isenergized vfrom grounded battery, its winding, righthand `front contactand armature of relay 93, outer front contact and armature otrelay 36,to ground. Relay 92 when operated, extends the impulse circuit 'from theregister sender to the conductors or' the selected trunk.

1t will be remembered that the relay 13 is locked in series with relay11 and when relay 14 opens the circuit of relay 11 it eiects thedeenergization of the relayv 13 lwhereupon the locking circuit includingrighthand winding of relay 18 is opened and this relay retracts itsarmatures. The link finder is of that type which remains in engagementwith the trunk last used so that this last described operation is allthat is necessary to effect it release. The link circuit in use is,however, guarded by the energization of relay 20, circuit of whichextends from ground, itswinding, lett-hand front contact and armature ofrelay 93, resistance to grounded battery. f

As soon as the trunk circuit of this description has been extended tothe distant oiice, the relay 97 of Figure 2 is energized from groundedbattery, its winding, through the upper winding of the repeating coil,back contact andL uppermost armature of relay 96, conductor 118 of thetrunk, conductor 197 through the brush of the trunk linder, c'onductor98, inner front contact and armature of relay92, sender nder brush 121,conduc-V tor 99, register controller brush 100 in its norinalposition,conductor 101, winding of relay 102 to ground. Relays 97 and 102 areboth energized in these circuits, the operation of relay 102 closes acircuit from ground, its armature and front contact, controller bi'iish103 in its normal position, back contact, armature and winding ot themotor magnet 104 to grounded battery. The motor magnet thus causes theadvance of the controller brushes into their zero position. T he relay97 of Fig. 2, however, when operated closes a circuit from ground,armature and Vcontact of this relay winding'o't` slow-releasing relay204 to grounded battery. Relay 204 is thus actuated and connects thelamp 105 in series with a'iiasher 106. Lamp 105 is therebyintermittently lighted to call the cperators attention to the fact lthata call is awaiting attention on the trunk to which this lamp isindividual.

As soon as the operator at the distant oice is in readiness to attend tothis call, Vshe depresses the assignment key 107 which extends a circuittrom ground through the Contact ci this key, upper winding of relay 96,conductor 108, the receiver brush 109 in its normal position, backcontact, armature and winding Vof the inotorY magnet 110 of the receiverswitch to grounded battery.

Relay 96 is also energized in this circuit and closes a locking circuitfor itself from grounded battery, contacts of release key 111, conductor112, winding of relay'113,

ico

conductor 114', lower winding of relay 96, its front contact landarmature, conductor 115, lower-most back 'contact and arma-ture ofrelay116 to ground.v Relay 113 is thereby actuated and closes a circuitby which the motor 1nagnetv110 is operated to advance the receiverbrushes into' their first position. Y Rel lay 96 when `operated alsoextends the conductors 116 andV 117 4leading to'the numerical receiver,to conductors 118 andf119 of' the trunk circuit. Relay 96when operatedalso opens the previously described circuit of 102 so that this relaydeenergizes and advances the sender switch into position 1.

With sender and receiver switches in' positionl, the registration storedup on the' register sender of Fig. 3 is communicated to thenumber-receiving device of Fig'. 2. This is effected in the'.tollowingpmanner. It will be'remeinbered that the stations relay isactuated in responsev tothe depression of the party key Jy, therefore',with relay 90 operated a circuit is closed from grounded batteryresistance. through the armature and front contactof relay 90, conductor120,*brush 100, conductor 99. brush 121, inner armature and frontcontact ot relay 92, 'conductors 98, 197 and 118, upper armature andfront contact of relay 96, conductor 116, receiver brush I122, conductor123,l winding oi. relay 124 to ground. Relay 124 is operated in thiscircuit and is locked actuatedover conductor 125, front contact of relay113 through the resistance to grounded battery. Also with the sender andreceiver switches in position 1, relay 126 (Fig. 3) is operated in acircuit traceable.`

troni grounded' battery through both wind'- ings in series of thisrelay, sender brush 127 in its first posit-ion, conductor 123, brush129. outer armature and front contact or relay 92, conductors 130, 131,and 119, inner armature and front Contact of relay 96, cou-I ductor 117,receiver brush 132 in itsfr'st position, lower winding of relay 133 toground; relay 133 remains inactive. In response to the energization ofrelay 126.,.thc motor magnet 104 of the sender switch has an operatingcircuit closed from' grounded battery, winding of this magnet, itsarmature and back contact, sender brush 103 in position 1, front contactand armature of relay 126 to ground. Under the control vof this circuitthe motor magnet advances the brushes of the sender switch into theirsecond position. At'this time a circuit is extended from groundedbattery, resistance, left-hand Vwinding ot relay 126, brush 12C7 in itssecond position. conductor 128,A brush 129, conductors 130, 131 and 119,armature and tront contact of relay 96, conductorll?, brush 132 in itsfirst position, low resistance winding of relay 133 to ground. Y remainsoperated and relay `133 attracts its armatureand thereby closes anoperating Relay .126v

circuit for the inotor magnet-*' of thereceiver-switch from groundedbattery-,winding armature and back Contact of this magnet, receiverbrush 1-34'in itsl'fii'st position, front contact and armatureofrelay133`to ground. The motor magnet is thus operated to advance Vthe brushesAof the Vreceiver switch into their second position. In position 2aeircuit is closed'from grounded bat` tery, low resistance windingofrelay 126, brush127 in its-'second position, conductor V128, brush129, armature and front contact of relay 92, conductors 130, 131 and119, inner armature and front contact of relay 96, conductor 117, brush132 in its second position through both the highf resistance and lowresistance windings in series of relay 133 to ground. Relay '126will'notremain operated in series with both windings of relay 133 AandYdeenergizes to complete va circuit from ground, its armaturef'and backAContact, brush 103 in itsv vsecond` position, Iback contact,arinatureand winding of the motor magnet 104 to grounded K battery. Under thecontrol ofthis circuit the brushes of the sender switch are advancedinto posi; tion 3. The circuit of relay 133 is opened and itdeenergizes' to vadvance the receiver switch into position 3. x Vith thesender and receiver switches both in position 3, the relay i.

relay 131 ,is actuated and'thereby closes a.

circuit for causingfthe'inotor magnet 104 to advance the sender s,witcliinto .position 4. This operationis e'ective toremove liighlresistance winding of relay 181 from; the

control circuit just described so that relay p isv operated to close theoperating circuit for the motor magnet 110 by which the re'- ceiverswitch isyafdvance'd intov position 4. When the receiver switch brush132 goes to 4, the high resist'ai'ice winding ofV 180`V is cut z. intocircuit and allows' relay 18,1 to*v release With the to move th'e'senderto position 5. l sender l.in positifonf, the circuit to 180 'isopenedand' itreleases to Amove the 'receiver to position 5. i

From the foregoing described operation of relays 126, 133", 181' and'180V it will be noted lthat first 'one of the relays of these pairs isoperated and subsequently the other relay of the' saine pair is operatedto {ad-jk Vance the receiver switchinto a succeeding position.' It willthus beseen that'the sender- 'switch is rst advanced oneY step tocomplete a circuit for advancing the receiver switch a single step andthis operation completes a circuit for' advancing the'seii'der switchinto.

icc

lil

its next succeeding position. This alternate advancing of' first thesender switch and then the receiver switch, each under the con trol ofthe other, insures that both switches will be in synchronism, so thatthe designation stored up on the relay registers may be transferredtorelays at the distant oiiice.

When the sender and receiver switches are passing through position 6, acircuit is closed from ground at the lower armature and front contact ofrelay, 68, conductor 137, brush 100, conductor 99, sender finder brush121, inner armature and front contact of relay 92, conductors 98, 197and 118, upper armature and front contact of relay 96, conductor 116,brush 122, winding of relay 138 to grounded battery. Relay 138 is thusoperated and is locked in this condition to ground over conductor 154.Vhen the sender and receiver switches are passing through position 11the registration stored up on the hundreds relay register is transferredtothe hundreds group of' relays at the distant oiice over a circuitcompleted from grounded battery, resistancei armature and front Contactof relay 80, cont uctor 139, brush and through the circuit previouslydescribed including the tip conductor 118 of the trunk to the distantoflice, to brush 122 of the receiver, conductor 140, winding of relay143 to ground. Relay 143 is thus operated and is locked actuated overthe conductor 125 to grounded battery at the armature and front contactof relay 113. As the sender and receiver switches are advanced throughposition 16, the registration stored up on the tens register istransmitted to the distant oice over conductor 141 and the tip side ofthe signalling circuit previously described, brush 122 ofthe receiverswitch, conductor 142,v winding of relay 144 to groundedbattery. Relay144 is thus energized and is locked operated to ground over conductor154. The registration stored up on the units register is transmitted tothe distant oliice over conductors 145 and 146 while the sender andreceiver switches arev passing throughV positions17 and 18, and thesementioned conductors are included in circuits for actuating relays 147and 149 at the distant office. Relay 147 when, actuated is locked inthis condition to grounded battery over conductor 125,Y while relay 149when operated, is locked in this condition to ground over conductor 154.It will thus be seen that the registration stored up at the originatingoiiice is repeated to the distant oliice and is there recorded on thegroups of relays designated thousands, hundreds, tens,

.units and stations.

At this time the release of the trunk finder, the sender finder and thesender switch is accomplished as will be described. When the brush 103of the sender switch reaches position 21 it closes a circuit foropingleses erating the release relay 96 appearing. at the I middle ofFigure 1. This circuit may be traced as extending from ground, windingof relay 96, front contact and armature of.

relay 36, sender brush 186, conductor 189,

.described impulse circuit while the relay 20 removes the guardingconditionr from the link circuit rendering it selectable for use/ on asucceeding call, also the operationof the relay 96 completes a circuitwhich will now operate marginal relay- 29 which-connects the trunkcircuit between the two oilices in question. relay 29 extends fromgrounded battery through the resistance armature and front contact ofrelay 96, brush 28, upper winding of relay 29, left-hand winding ofrelay 26 to ground at the armature and back contact of a relay similarto 26 associated with an idle trunk or if all of the trunks are busy,through the winding of relay 21 to ground.

In accordance with the present invention it is proposed to have one setof ten numerical lamps and four station lamps. The stations designationof ithe wanted subscriber first appears on one of the stations lamps andthereafter the digits of this designation appear one at a time on theten numerical lamps appearing at the 'lower part of Fig. 2. This iseffected as will now be described.

When the receiver switch is advanced into position 21 it `closes acircuit from grounded battery, winding of the motor magnet 110, itsarmature and back Contact, brush 134,'conductor 155, winding of relay156 to ground. Relay 156 when thus operated closes Va circuit for themotor magnet 157 of a small distributor switchprovided with five sets orbrushes disclosed adjacent to each other, near the center otF'ig. 2.yl`he This operating circuit of the operating circuit for this motormagnet exsubsequently to the groups of tens and units .Y

relays that have been actuated. It has been assumed that the vfirstdigit of the wanted number is 2, and it will be observed by tracing outvthe eircitjfr fatutnfg Lamp No. 2 that "relay 152 inistjhefoperated.This Ais fetfecitedfw'hen the bruishl'15-8 'of ithe distributor switchjpassiiifg' fthrouzgh its :sec-

ond position, at `ufhichftiine `theI "relay 152g'.

is connected to "ground multiple yiith Aactuated thousands relay138,jouerfc'onductor 154. Since the 'neii-t- Vdigit is 3 jis necessaryto light the No. lamp Whichg'ixs effec-ted by actuating relay 151. Relay151 is joperated When the brush, '159 of Lth'edistributo-r is 4advancedl'to 'position 4 where- 'a circ-uit is completedfoverconductor to theAfrontvcontact and armature -rof "actuated hundreds relayl 143, to `Lfgr'o'unded battery over conductor 125. 'In order `to li'ghtfthe No. 4;larn'p 'it isf,necessary tofac'tuatejrellay and this is-eife'ctedtiihenvthe,brush 160 of .the distributor 'switch visad'v'a'nced-'te its siXth position Where -a Iciiuit. is completed 4overconductor 142 andthe front contact lig'ht vth'efNfo. lai'iipli-t fisnecessary. topper- 'ate bjothfthejelays 15e '211111,153. ,Thiersefgfetted 'when the distribuer tras-hes 15e faire 161 yare adi/landed'vihtoftheii' eighth lposition "at which ftiine relay A[is Ardperated'in 'a ',oi'r- 'cu'it `dosed 'frein gri Yrfdvd batteijy,wfv'inding O'fthis relay, distributorbrushie,armature fand "front contaet ,ofactu'ated unitswrela'y 149 yto ground, ever conductor A1545 Relay 153 isoperated in "a circuit traceableffrorn grppnd, its wi-riding,'distributor huish, 161, conductorv 163, froiit, 'contact 'andarrri'a'tu're of 'a 'second actuated unitsfrel'ayf147, `to grounded-batterfy oifer 'cond-uctor( 125. It will -o-t cour'sefhe understoodthat the speed of operatin ofthe .distributor Asitz'itch Ycan he Variedat will, so 'thatfthe various lamps Willremai'n lighted long 'enough Vsothat the operator can ascertainthedesigna- -tion of the Wanted nuniber.In the yevent that the .operatordid not 'observe the designationindicated by :the Alamps on the first rotation of the distributorsu'fitch,l it will continue to rotate until the Qperator'receives thedesignation ,and inserts vthe vcia-lling 'plug' 164 in the multiple jack165 of the called line.v Y f i *y ,u Y`When 'the `operator effects thisconnection, relay 116 associated'zf-With the connecting cord circuit isoperated froin'grounded battary., itsvwinding, the sleeves ofthe plug16.4 and jack 165A seriesiWit-h' the 'cut-'off relay 166 Jtogroundm'Relayl-l fattracts its arinatures and fat .its 'upper a-'rrnagture. closesI athreakfpoiirt int-he -tipside pf theA cord. circuit. H,At."tl1e iiiIei. a-ii-n'atli're :and front contact of, relayg1'1i6abreak-'po-int is `closed iin the circuit of the'supfervisory lamp 105`in series 'with the [pilot relay, but this 4circuit :is ineffective at,thisftme A.Since the, relay-'294 ,iS-Qt'erateft Mirthe Innerer.- rnatureand Aloac'k contaft of relay 116,

Y ry"fro1`n the 'hol .h ding gri-Und 'f the right-hand ar -fef'fanaback; edited dinggconductor 125 and 'i condli'ctor. 154. At 1 Qfrelayiia, afefsformgeircuit islcloseu fer rinature. 'and vback[Contactof v'relay del jjfithis iastj'deseri-bed dreun; the brushes V109, l122,ierland-132m 'the receiver switch are advanced into "theirno'rmalljposition.vk As soon as brush 13,4Jo`f the receiver Vswitchleaves f'pofsitio'n v'ti'wlveln'ty one, yrelay 156 deth tering 'circuitis closed for re iaiid.-yoaak1dontagii; the meter maget, brush 167 .ofthe "di'stribiiteiv-fsvfvitch in anyNfone` of its olf-normal positions,to

:After atelier-ternes iiistart-'ea` tapping i 1621 into Vthe multiplei-jack '165,` she depresses @neef the "ringing,V keys to 'supply ,ringingfcu' rent,'ofth'e"p'roper character to signal sta- "tionffJll,onthe-Wanted line. Let itV be as- "su'inedrfthat, the key No. iisithekey for :signalling party J, l,W'hen 'the vkey 168 1s depressed it.fcloses-its contacts 178 to aotiia'te 'the/ringing vrelay .f 171 in facircuit extendingfoin grounded battery, resistance,

upper 'winding'foffthisrelay, contacts "178` backcontact'andfarinatureof relay 176 to ground .at the Y uppermost armature and figont -Contact.of relay .2021.-` The ringing relay when loperated .closes .a lockingcircuit for itselfthrough its lower windin'gf,inner front contact 'andarmature to ground at the uppermost` arinatu re and front contact ofy'relayQOl. n lith the 'ringing key 1168 depressed and yvith the,ringinlgfrelay V11/'1 'locked operated,a sourcex'of ringing` current isconnected over conductor y 169, contacts of the 'rilrigin'g` key 168 andlnormal `contacts ofthe other keys precedingfit inseries, lower front er'switthwhich extends, 'from t 5 a. ture,ahdjbaekeentactiof,relay 11,56,

vcontact xand.a 1rna'ture of relay 2021, Windof Athejtri-p -relay170,:lower1nost front Contact afndarrhatuiie of; the ringing relay `171, uring,conductfo f`rl of .the=.eord, ring centac'ts of ,the ,plugw164v and 'jack 165,. over r"the lowerf snide of the 'want dflinef'through 4"the hell2 eircuit 'ot station .rJ,;oyer,-t he l upper side'ofthe "Waiite'drhline `through 'the' ftip. contacts of thej ack .,165vvand noyer the tip 1163211161; thro-ugh I.theire- Contact bf ,ffelayfSieben@ @9eme the control of this circuit the bell-.at station J isactuated untilthesubscriber there at responds, at which vtime thetriprelay 170 will receive suiiicientv current to be actuated andattracts its armature. rfhis short-circuits the ringing relayA "171 andthereby causes it to `'retract its armatures tov disconnect ringingcurrent from the wanted line and to close a break-point in the ringconductor off the cord circuit.

Talking battery is suppliedvto the called party through the` windingsofsupervisory relay 172 and when the called party responds, this relay isactuated to complete a circuit for relay 173 in series withthesupervisory relay 1740ic the cord circuit at the originating oice. Toprovide supervision at .the originating oiiice, relay 173 is o peratedin series with the relay-174 of the cord circuit at the originatingoice, while to give supervision to the terminating operator, the tipside of the circuit is connected through the.r windings of relays 17 5and 97. K Talking battery is lsupplied to the calling partythrough theleft-handwindings of the repeating coil in the-A operators cord circuit.

Vhen the calling subscriber A terminates the call, a supervisory relaysuch as 17 9 is released in the operatoids cord circuit at the ture ofrelay 116, winding .of the pilot relayv to ground. v

In the event that .the called party terminates the connection byreplacing Ahis receii'eron its switch-hook before the calling partyhangs up, thenthe relay 172 decnergizes and opens the circuit includingrelays 1.73. and 174. Relay 174 will then deenergize to light adisconnect lamp not shownll at the A operators position. This operator.will then proceed to remove the plugs 4.and 7 ofthe jacks 5 .and 8.

'In Figs. 4 and ,5 there are shown modified circuits for the wanted oiceto replace those otFig. 2. 1t will be understood of course that thecircuitsof Fig. 4.are to be connected to those of Fig. 1 and operate ina manner identical with the circuits controlling the receiver vswitchyand theY talking circuit' of Fig. 2. In 5, however, there is a somewhatmodified arrangement for con- Ithe -wanted station. `will beunderstoodof course that the number is stored up in the saine manneras."

thousands and hundreds digits and subsequently light the tens and unitslamps corresponding to the tens and units digitsof In 'this modiiication1t previously described on the relay registers of Fig.4 3. It will alsobe understood'that the! sender VVswitch of Fig. 3 will operate inconnection with a receiver switch at Fig. 4 `in thesame manner aspreviously,described. lAlso in this operation some of the relays of thethousands, hundreds, tens and units vrelays will be actuated and lockedoperated in the manner previously described'q It ywill now be assumedthat vktheniodii fied circuits of Figs. 4 and 5 are. to be 'used insteadof the circuits of Fig. 2. It will also be assumed thatthe designationot the A'wt-inted party is Main 2345-fJ-,asin the previous case. Itwill'be noted in Figs. 4 and 5 that the same reference characters havebeen applied to the vportions of Figsi'4 and 5 that are identical withFig. 2, which willrender it unnecessary to describe the operation ci thereceiver switch or the receipt and storing of the designation onthethousands, hundreds, tens, units and sta'- tions groups of relays ofigure 5.` The descriptio-n may therefore be taken up at the point wherethe thousands relay 138 and the Il@ f hundreds relay 143, tens relay144, the units relays 1 47 and 149, and the stations relay 124 havebeen' lockedactuated. It will also be assumed that the receiver switchhas been advanced to position 217 in which position acircuit iscompleted over conductor 155 to actuate the relay 156, As in theprevious case this effects the operation of the motor magnet 157 whichadvances the vbrushes of the small distributor switch in the same manneras in the first. described circuits.

It will be remembered that in theiirst modification the numeral lampswere lighted one at a time to. indicate the desired number, butin themodification now under consideratiomtwo numeral lamps arelighted.simultaneously.V This is effected in the following manner: Whilethe brush 158 of the distributor switch is passing through position 2gthe leftdiand winding of .relay 201 isconnected in a circuit in multiplewith the relay 138 ot the thousands groups of relays. .This circuit .mayVbe tracedk from grounded battery, left-hand winding et re-V ture ofrelay 156. Wheil vthe,.hetrlb brush 200 isA Y21 lv2f1`11ccl fofpotti heswitching .rely'QOQiS ooerate vi 1`1'zrl'e closed to groundthroughfhfebrshQOOf when the ,distributor Aswitch tion ll,v relayQ'Orh's an oier llt closed ,from,.groun'd, its .right-hemd yvlndgng,front Contact 4and 'arnit'resjo'f "rel brs'h 1597 conductorf140`,rfrofri't oarmature of: relziy 143l to he tery yover oohcllto'r 125,.lRel opertecl isflooke n thifs'oondl its left-hand frot polgatfs'd ground-ltgtheffroIlt-oo [al of relay 156', and Whilefl'e distrib Y 200 ispassing, through postops, 6 n

a 'lamp in each of l A' ated. It will bfe notdthat. rel'ziyZQ position2. 2,001'

ors- 'p'slhon Yfor iut to (a wanted right-hand arliaflre c'i'o lay 203through the No. Sla Contact and ,armature oi` utor brushQOOfto.QThe',.:Noz

info al meipl'e raf@ positions, a terminating oflice having a Boperators position, telephone lines terminating in each operatorsposition, trunk circuits terminating at said A operators positions,means for connectingtsaid" trunk circuits to said B operators position,a cord circuit'at cachot1 said A operators7 positions 'for connecting acalling line to a trunk circuit, a plurality otregister senders'commonto said A operators positions, means responsive to the connectionof a cord circuit tov atrunk circuit for seizing a register sender foruse, means for. variably adjusting said seized register sender, anindicating device at said B operators position arranged to be variablyoperated in accordance with the adjustment of said register sender,means for synchronizing said sender and indicating device andmeansjcontrolled at said B opverators position for 'connectingsaid trunkcircuit to a wanted line. .4. In a telephone system, an-Aoperatorsposition, a B operators position, a trunk circuit for connecting saidpositions, telephone lines terminating at each of saidp'ositions, meansfor connecting aca'll-ing line at thel A7 Ioperators position to saidtrunk circuit, a variably operable sender at said A operators positionarranged to be adjusted iii-accordance. with theV designation of thewanted line, a single set of tennumerical keys at said A operatorsposition for adjusting said sender a receiver at said B operatorsposition comprising receiving mechanism for each digit of the-wantednumber,vsaid receiver being adjusted from said senderlampsassociatedtherewith less in number thanthe number of said mechanisms andmeans forconnecting said Vtrunk circuit-to a wanted telephone line as indicated.Y

5. In a telephone system, an- A operator7s position, a B operatorsposition, a trunk circuit forconnecting said positions, telephonelinesterminating at each of said positions, means for connecting a callingline at the A operators position to said trunk circuit, a variablyoperablesender at said-A operators position arranged hto be adjusted inaccordance with the. designation of the wanted line, a receiver at saidB operator-s position comprising receiving mechanisms Vfor each digitofthe wantedA number, sets of lampsassociated therewith less in. numberthanthe number of said mechanisms, `means for synchronizing theoperation of said sender and, adjusted receiver, and means forconnecting said ,trunk circuit to a wanted telephone line as indicated.n Y n l y 6. In a telephoneV system, an A operators position, a Boperators position, a trunk circuit for connecting said positions,telephonerlines terminating in each position,

f vmeans for connecting a calling telephone incassa line at said A oerators osition'to said atrunk circuit, av variably operable sendingdevice connectible to said trunk circuit, a receiving deviceV atsaid Boperators position comprising a set of receiving mechanisms, one foreach digit of the wanted number, said mechansms being arranged to bevariably operated under the control of said sender, a'single set ofkeysat the A operators positionv for controlling the operation offs'aidsender, means for locking the mechanisms in their actuated condition, asingleV Vset ,of indicating lamps arranged to beY opsition arranged tobe variably adjusted in accordance with the designation of the wanted`line, means for connecting said senderto f said trunk, a group ofreceiving. relays at said B operators position arranged to be variablyoperated under the control of said sender over said. trunk,aysetofhindicating lamps repeatedly operated under the control of twodi'erent groups of relays, and means 'for-connecting said trunk circuitto a wantedA line as indicated.

. "8. In a telephoneisystem, an originating office, a pluralityvof otheroiiices, telephone linesterminating ateach of said oiiices, an jindividual group of secondary trunks leading to each of said officesfrom the said originating office, a group of primary trunks at theoriginating otlice for each oiiice reached therefrom, each primary trunkterminating atene end in a manual switch, automatic means for connectingthe other end of each primary `trunk to an idle secondary trunk, meansresponsive 'to' the manual connection of a calling line to a primarytrunk to eii'ect the selection of4 an idle secondary trunk, meansresponsive to such selection to cause said automatic means to seize .theselected secondary trunk, Aa plurality of register senders for commonuse'at said originating oiiic'e, means for associating-'an Yidleregistersenden Vwith the selected secondary trunk, meansfor variably adjustingsaid selected senderin accordance with the designation ofthe wantedline, ymeans associated ywith the selected'trunk atthe distant oice andoperatedlover said selected trunk under the control of the adjustedregister sender for indicating thereat thedesignation of the wantedline, and means at the wanted cnice lessees,

forv completing the connectiony inI accordance Withsuchdesignation. n 9-In a, telephone System,.an originating office,l a distant office, apluralityv of l opera?` tors positionsatl each of said offices, tel'ephone lines terminating at eacliuof said of# ices,I trunk-circuitsiforconnectingfsaid offices, certain of which terminateatfthe originatingyoiiiceI in jacks, operators` cord circuits at the originating o'iiicetorconnetinga calling line through ay jack to a1 trfunl` leading` to said:distant v'otlic`e,l a key-set atl each operators p osition, aplurality'iof register senders common to a plurality,- o'i po-iY sitionsatsaid originatingoliice, means.. re-Y sponsive to the connection, of ajcalling line toa trunk for associating. an ,idle register sender with,said;v trunk and fon connecting thezsame to the key-setoffthe operatorthat.

has completed theY connection, ofthe'. callingv line to the trunk, saidregister sender beg-'l ing variably operated lin accordancewithV thedesignation et,v thev `Wantedline), underil the control of saidoperators key-set, means associated With the, operators. positions atthe distant office and operated under the control of the adjustedregister senderY for indicating the designation of the Wanted telephoneline at one of said last-mentioned operators positions, and means atthis lastmentioned operators position for completing the extendedconnection.

10.' In a telephone system, an originating oiiice, a distant oi'ice,telephone lines terminating at each of said oiiices, trunk circuits forconnecting said offices, a plurality of operators positions at theoriginating office in eachY of which telephone lines terminate, aplurality of trunk circuits and means at the originating oflice forconnecting the same to calling telephone lines, a plurality of registersendersrcommon to said operators positions, means for associating aregister sender With one trunk circuit leading to the distant oiiice,means at each of said positions for varia-bly adjusting a registersender in accordance With the designation of a Wanted telephone line atthe distant oilice, an operators position at the distant oiiice in Whichsaid trunk circuit terminates, a set of numerical lamps at the distantofce, means at this oiiice operating under the control of a singleadjustment of said register sender for operating said lamps a pluralityof times to give the designation of the wanted line, and means forconnecting the extended trunk circuit to said Wanted line.

1l. In a telephone system, an A operators position, a B operatorsposition, a trunk circuit connecting said positions, telephone linesterminating at said positions, means for connecting a calling line atthe A operators position to said trunk circuit, a

variably operable sender at said A operatei-fs position be adjusted. inaccordance,

designation, dfi-the.' ivanted'j tele-j; e; a'receverll said'.BL'oper-tofrs comprising; 'mechanism for @aanv Wit dig j die wanted'number, said(E receiver loV adjusted; under the; controlgof, saidsender,T on more ,sets of; lamps associated With, sa" y i thanwtli'e" n,lbenorfisafd mechanisms, means foriV connectjinfr saidfmechansms insuccestoj 'saidgj farnfps,A andi: means for connectingsadtrunlfcircuit'to a. wanted tele- 1:94 In a'telephone system, operatoris adjusted" in;werden@ gaat. .the designation,

Wanted, telephone, line, a receiver'fat ofc'ftlie said'B oerjatorsgposition, comprisingja receirnamaliaam.- for. eahsdigiffoftheWa.nted"number, 'sa-id Vreceiver'y being adjusted under the control ofsaid sender, one or more sets of lamps associated With said receiverswitch less in number than the number of said mechanisms, aprogressively movable switch for connecting said sets of lamps to saidmechanisms in succession, and means for connecting said trunk circuit toa Wanted telephone line.

13. In a telephone system, an originating olice having an A operatorsposition, ,a terminating office having a B operators position,telephone-lines terminating at each operators position, a primary trunkcircuit terminating at said A operators position, a plurality ofsecondary trunks terminat-ing at said B operators position, an automaticswitch for extending said primary trunk to a selected secondary trunlnaplurality of register senders at said A- operators position, a linlrcircuit terminating at each end in a progressively movable switch forconnecting an idle register sender to a secondary trunk, meansresponsive to the connection of said link circuit to said secondarytrunk for causing said automatic switch to extend the primary trunktothe position, a B operators position-,telephone linesterminating ineach of said positlons, aV primary trunk terminating in said A;operators position, manual means for connect`V ing a calling telephoneline at anA operators position to said primary trunk, a plurality ofsecondaryy .trunks extending to said B operators position, a plurality'of register senders, link circuits each terminating at its ends inprogressively movable switches, a link finder switch, means operatingresponsive to the connection of said calling telephone line to saidprimary trunk for causing said link finder to seize an Aidle B operatorsposition` means including said adjusted register sender forvariably operating said indicating device to variably indicate the designation of thewanted tele-y phone line, and manual means. at said`B`- operatorsposition for extending the select` ed secondary trunk to said wantedtelephone' line. A

l5. In a telephone system, an originating ofice, a distant office,telephone lines terminating at each of said oiices, trunk circuitsYinterconnecting said oiices, means at the originatmg omce for connectinga calling telephone line through a trunk to said distantolfice, a senderat the originating oiice variably operable in accordance with thedesignation of the Wanted telephone line,

an indicating device at said second oiliceY arranged to be controlled bysaid sender,

manual means for connecting. the Vextended telephone lineto the Wantedtelephone line,

andmeans for causing said indicating devicerto repeat its designationuntil the oper-- ation of said manual means.

In witness whereof, I hereunto subscribe my namethis 31st day of MarchA. D. 1921.

WINFRED T. POWELL. Y

